A chilling case of an 18-year-old, Tristan Thomas Roberts, who recorded himself holding his mother captive before brutally slaughtering her with a hammer, has now reached its legal conclusion.
According to investigators, the teenager had spent weeks researching the e*ecution, posting disturbing misogynistic messages online, and even documenting the final hours of his mother’s life.
The case, heard at Mold Crown Court on March 25, 2026, exposed a disturbing trail of planning, digital evidence, and chilling recordings that captured the moments leading up to the butchery.
An 18-year-old teenager recorded himself holding his mother hostage before fatally wounding her
Image credits: North Wales Police
Roberts assassinated his mother, Angela Shellis, a 45-year-old teaching assistant, after holding her captive inside their home in Prestatyn, North Wales, on the night of October 23, 2025.
Prosecutors alleged in court that Roberts recorded the entire ordeal on a digital audio device. The recording, which reportedly lasted more than four hours, captured the attack beginning inside the family home before ending with the fatal blows.
Andrew Thomas KC, prosecuting, revealed the recording covered “everything from the initial a*sault to the fatal blows at the end.”
Image credits: Angela Shellis/Facebook
At the beginning of the audio, Roberts could be heard saying, “This is the moment we are doing it. We are going to hit her with a sledgehammer.”
The court heard he first ambushed Shellis in her bedroom with a hammer and strangled her before keeping her prisoner for hours while threatening her with the weapon.
Despite the terrifying situation, Shellis remained calm and repeatedly asked him to call 999 for medical help.
After torturing Shellis for hours, Roberts lured her to a nature reserve before delivering the final blows with a hammer
Image credits: North Wales Police
After hours of captivity, Roberts convinced his injured mother to leave the house under the pretense that he was taking her to get help.
Instead, he led her to Coed y Morfa nature reserve, where he carried a hammer inside a rucksack.
A ring doorbell footage from a nearby home showed the pair leaving their house at 3:19 a.m. and walking toward the nature reserve.
Image credits: North Wales Police
After reaching there, Roberts took the weapon from his bag and began repeatedly striking her in the head.
Shellis passed away from her catastrophic injuries.
Walkers discovered her body in the undergrowth near a footpath later that morning on October 24. Investigators also found a 100-meter trail of blood along the gravel path leading to the scene.
Image credits: North Wales Police
After returning home alone at 5:35 a.m., Roberts logged onto the online chat platform, Discord, where he boasted about the incident.
“I’ve just had the craziest day,” he wrote, claiming he had “smashed her skull in so hard with a sledgehammer.”
Police arrested him later that day at the family home.
During the investigation, officials discovered that Roberts’ online posts revealed weeks of planning and violent misogynistic views
Image credits: North Wales Police
Investigators discovered extensive evidence showing Roberts had planned the attack.
According to the investigation, he had spent weeks posting messages on Discord about violence, weapons, and attacking his mother. Despite repeatedly being banned, he returned to the platform under multiple aliases.
In one message, he wrote about his “hatred of women.” In others, he discussed possible ways to assassinate his mother.
The court heard he also used the AI search engine tool, DeepSeek, to research e*ecution methods, asking questions about which weapon would be better for a “non-experienced k*ller.”
Image credits: North Wales Police
Furthermore, Roberts had waited until turning 18 so that he could legally purchase weapons online and in stores. His purchases included axes, knives, hammers, a balaclava, gloves, and overalls.
On the night of the attack, he even recorded a message beforehand, saying, “This is Tristan Roberts. Tonight I’m going to be Alex, and I’m going to m*rder my mother with a sledgehammer.”
Prosecutors further claimed he had a fascination with fictional serial k*llers, including the television series Dexter and the film American Psycho.
Beyond Roberts’ planning, the court also shared that Shellis had repeatedly sought help for her son
Image credits: North Wales Police
Shellis had reportedly spent months seeking help for Roberts as his behavior became increasingly concerning.
Just days before the incident, she contacted a social worker and friends after discovering he had purchased weapons.
In a note saved on her phone, she wrote, “Why?? What does he need these for? Is he planning to hurt me, himself, what? Who? Why?”
Originally from North Wales, Shellis had returned to the area after divorcing her husband and worked as a teaching assistant at Rhyl High School so she could spend more time with her children.
Her older son, Ethan, who was away at university at the time of the incident, later told the court that his mother had always tried to support Roberts.
“All my mum ever did was love Tristan,” he said.
“I don’t know how he could have done this to anyone, let alone the one person out of everybody who would do anything for him.”
Shelli’s sister, Sarah Gunther, also remembered her as a devoted mother who never gave up on her children.
“She had so many amazing qualities, but one of the greatest was the way she devoted herself to her boys. She was a fantastic and fiercely supportive mum, the kind who never gave up, no matter how hard life became.”
“She fought tirelessly for them, and her love for them was unbreakable, a source of strength that carried her and her boys through every challenge.”
“She will be missed every single day by so many people whose lives she touched,” she added.
Besides her older son and sister, a Judge also described Roberts’ crimes as “truly awful” while sentencing him to life in prison
Image credits: North Wales Police
Judge Rhys Rowlands described the crime as exceptionally cruel.
“You appear to have revelled in the control you exerted over your own mother,” he said. “It was on any view a truly awful way for someone to d*e.”
The judge further noted that Shellis must have been terrified during her final moments.
“Callously, you ignored her pleas. She must have been truly terrified in these, the last moments of her life,” he said.
Image credits: North Wales Police
Although Roberts had been diagnosed with autism and ADHD, psychiatric experts revealed to the court that he understood his actions and was capable of exercising self-control.
After the sentencing, senior investigating officer Temporary Detective Superintendent Andrew Gibson said Shellis had shown remarkable courage during the ordeal.
“She showed tremendous bravery on that fateful night”, he said, adding that she remained calm and continued to show care for her son despite the terrifying circumstances.
“I hope today’s sentencing allows for some closure and supports Angela’s family in moving forward and towards rebuilding their lives.”
At Mold Crown Court, Roberts was sentenced to life imprisonment with a minimum term of 22 years and six months after pleading guilty to homicide.
“Shouldn’t be let back out at all,” wrote one netizen
